Fellow HAMBers, August of last year I purchased a great 1963 Chevy II wagon. I've been wanting a family cruiser for quite some time as my wife and kids really enjoy old cars, car shows and cruising. Obviously my Model A Coupe is not going to get a family of 4 around. My wife said, "I want a family hot rod, too". This Nova practically fell in my lap and it was one of those instances where it was....if you're going to do this...this is the one to buy and now is the time. It's a solid car and still has the red oxide primer on the undercarriage from the factory. It was however (and still is) set up for drag racing. I know swapping out the TH350 transmission is the obvious and probably "right" thing to do. However, I was hoping I could change the center carrier and achieve my goal. This is what I would like to accomplish: 65 -70 MPH at around 2,200 to 2,400 RPM. What I'm really trying to get is just a nice family cruiser. I like to attend several car shows that are a couple hours drive from my house, so it needs to cruise down the highway and/or Interstate. Here is the current set-up: Engine: 400 SBC (about 4,000 miles on the engine) Mild Cam hydraulic flat tappet (unfortunatly I do not have the specs) Dyno'd at 383 HP (494 tq) Vortec heads Holley 650 double pumper Ran 12.80 in the 1/4 mile Trans TH350 Trans with 3,200 stall converter Rearend New Ford 9", aftermarket axles, Posi The paperwork states it has 3.50 gears Rear Tires P235/70/15 (That is the absolute largest tire you car squeeze into that wheel well without rubbing) HHmmmmmm, although the paperwork states it has 3.50 gears, I swear the car acts more like it has 4.11's. Currently it goes down the road at 65 MPH at about 3,500 RPM's (the engine is just screaming and I don't feel like Im going too fast...and traffic is flying past me) I contacted a local drive-line shop and I inquired about just a Ring & Pinion swap. He quoted me between $2,000 and $2,400. Well for that I could buy a fully set-up Currie posi center carrier and just bolt it in and it would only cost about $1,300. I have a friend coming over soon. We are going to pull an axle and count the splines. We're also going to pull the carrier and count the teeth on the gears to verify the actual gear ratio. My question for you fine gentleman is this........Which gears would be best suited for this car given it's set-up so I can achieve a reasonable cruising RPM? (3,500 is just too crazy) Thank you for your help and knowledge. The rear tire is a tight fit, but does not rub
3.08 gears. ditch the 3200 stall for 1800 stall. That gets you 2600 rpm at 70. Any lower would require different rear end or overdrive. Remove cover and you should see number of teeth stamped on ring gear. That will tell you what it has now.
If you can find a dropout in a yard it will be close to 3:1, I like 3.25:1 in the. Fairlane with the miled motor.
That's a really cool ride! If it's doing 3500 rpm at 65mph, yeah, it has to be a 4.11, maybe a 4.30 or 4.56. You can use a gear/speed calculator to figure it out. For nice driver, I'm with fastcar. 3.00 or thereabouts. The converter is way too loose for a driver IMO. The problem is not knowing the cam specs. If the cam has a good bit of duration, a tighter stock-like converter is gonna be a problem.
More work and more money, but a 200R4 should fit in there. I’ve never replaced a 350, but I’ve done a couple poweglides. The o/d (with 4:11’s) would give you an effective 2.9 at cruise, and a 400 with a mild cam should handle that at 2500 rpm or so. Depends how many miles of cruising you’re doing. Even with a tighter converter (and lock up) you’ll still have most of the performance. 12.8’s aren’t too shabby. Plugging in a 25.5” tire and 65mph gives a cruise rpm of 3520 rpm with a 4:11
I suspect the high stall is the reason for the high rpm, until it reaches the stall, the converter is slipping. If you change the rear gear and lower the cruising rpm, that converter will always be slipping. At the price of the gear change, I would leave the current gear there (provided it is a 3:50 something) and just go with an OD trans with a low rpm lock up converter. The rear gear would get the car moving better, and the OD trans would knock down the cruising rpm range. The OD trans swap might be cheaper then the rear gear swap, and you would still need to get rid of the high stall converter.
What's that converter doing in there, with a mild cam? Does it have a tach? Is the speedo accurate? You can figure out the gear ratio without taking anything apart....just turn both tires one turn (or turn one tire two turns, if it's not posi/locker) and count the turns of the driveshaft. If the driveshaft turns 3 and a half turns, then it's 3.50 ratio gears. But yeah....I'd figure out what the cam is first, and then set up the rest of the car to work with it, or change it to what you want. Stock converter or one step up from stock, with 2.75 rear gears, will be pretty nice. I'm basing that on it being a big engine in a relatively light car. used to be you could get anyone to give you a set of used 2.75 gears, but they're getting harder to find these days.
They made all sorts of nosebleed tall gears for 9" Fords. You could probably get a whole center section off Ebay all setup with what you need for less than $1000 probably. Ditch the loose converter like others have said.
Checking the ratio as @squirrel suggested, and pulling the axle to count the splines is the right step. After market axles are usually 31 spline, but could be 35 spline, especially since set up for drag racing. Most factory Ford center sections were 28 or 31 spline for cars, and 31 for most trucks. Common Ford ratios were 3.00 for cars, 3.25 for HP cars, and 3.50 for trucks. If your axles are 35, I would opt for a ring and pinion swap in the 3.00 to 3.25 range, and change the converter to a lower stall.
Go with an OD trans and leave the rear gears as they are. I run 3.42's in my cpe and when it first built I ran a T-350. It was 3k or a bit over at 70 mph, 22K mi. later I changed it to a 700R-4 no regrets and about 2100 rpm at 70. I now have 99+K on it. Depending on which T-350 you have you may only need to change the tranny mount position as the driveshaft might be the right length. My 350 had the right tailshaft length that made it possible for the driveshaft to fit
I second the 2004r,close to the same size and gears but overdrive is a .67 and change converter.Nice car.
If the 350 has a 6" tail shaft the 200R is the same length, but a 9" tail shaft makes the 700R 1/16 different. The 9" tail is what I had . Do you think the difference from .70 to .67 is really that much? I don't. Trans mount for a 350 is 20 3/8" back, 200R is 27" and the 700R is 22 1/2"
The crossmember on the early Chevy II is a bit more involved...you can't just slide it back, you gotta buy one made for it, or do some fabrication. This is an issue with either the 200 or 700 overdrives. Swapping the transmission is probably going to cost at least what the shop quoted him for gears. Probably a lot more from that same shop Might be that overdrive is the only thing that will make him happy though, seems that not many guys are into driving cars like they used to be driven, with the engine singing merrily along.
I am pretty sure I know that car , A friend of mine built it about 6-7 years ago. he had a 4 speed in it for a while and I think I see the floor patch where the shifter was, Ditch that slippy convertor and report back...... are you sure the tach is accurate? My corvette has 3.55's and is at about 2800 at 70 and it doesn't bother me a bit. the car sure doesn't care. People are bothered by cruising rpms because they are used to their modern econobox cars....
Thank you to each and every one of you for the sound advice. My apologies it has taken several days for me to reply. Last week was a 72 hour work week, so I have been away. Yep, that converter has to go as it's only hindering my goal and it's mostly pointless for my indented application. @Bangingoldtin makes a great point and I'm quite curious as to which spine axels are in the car, since they're aftermarket. Thank you @squirrel I was wondering which transmission would require crossmember work, thank you for the clarification. I greatly appreciate all your responses and I m looking to to reporting back with the combination/solution. You are correct @Moriarity From what I understand this car spent the majority of its life in the southern Colorado/Northern New Mexico area of the US; which explains why it's in such remarkable condition. It was then purchased and brought to the Twin Cities where a few guys made a lot of awesome mods to the car. It indeed had a 4 speed (which I wish it still had) in fact, the clutch pedal is still in the car. It was then purchased by a guy in St. Cloud. Several years ago my dad spotted an ad in the Line Chaser and went to look at it. He bought the car that day. Last year my dad was looking to downsize his car collection so I jumped at the chance to buy it.
With 215/70R15 tires and 2.72 gears, you will be able to cruise at approximately 65mph at 2200 rpm/w TH350. Although 235 tires are a bit taller, you'll still need a axle ratio of less than 3.00/w TH350. If your 400 dynoed at 383 hp, it probably has decent compression, heads, and not exactly a mild cam. 3200 stall converter not a good match for a mild cam, and certainly not if you want to cruise at 2200-2400 rpm. A 3200-stall converter will slip significantly at 2200-2400; your mpg will suffer, and torque converter/transmission won't last long. However, the 700R4 does have a lock-up converter, which will help. Before you start swapping gears/transmissions, you need to get the cam card for the camshaft in your engine.
Like everyone has stated to ditch the converter in place of a good stock unit. Once you find out the spline count you can look around for a 2.75 or 3.00 gears. If you can just buy a used center chunk the 3.00s around here are plentiful and cheap (I have a few out of pick a parts).......I even have a 2.47 for something .
Stock converters are pretty cheap. Toss one in and see what it does. My local parts store has a baseline 1969 Chevelle TH350 converter for about $100 out-the-door.
P.S. If your goal is to have a family-friendly cruiser wagon/w automatic transmission, I would get rid of the double-pump carburetor and replace it with a vacuum-secondary carb. Take a look at Summit's 750 cfm carb. Your carburetor is better suited for a manual transmission.
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